Shiftable ladder installation

ABSTRACT

A guide follower assembly secured to the lower portion of an inclined ladder engages a downwardly open guide rail channel for stabilizing the position of the lower portion of a ladder with respect to the guide rails, the upper portion of the ladder being supported in conventional fashion by a follower engaging an upper guide rail. The ladder is inclined in a vertical plane parallel to the guide rails, and the lower follower is mounted on an arm extending preferably from the underside of the ladder, as inclined.

22 Filed;

Unite States Patent [191 Freiburger SHIFT ABLE LADDER INSTALLATION 76] Inventor: Joseph Anthony Freiburger, 2037 Edgewood, N.E., Grand Rapids, Mich.

Oct. 15, 1969 21 Appl. No.: 866,596

[52] US. Cl ..182/39 51 Int. 01...; ..E06c1/397 58 Field of Search ..1s2/39, 38,36;

[56] v References Cited UNITED STATES PATENTS 3 12;015 -4/1967' Plegat ..49 410 383,449 5/l883 Eiden ..l82/38 [4s] Apr.24,1973

Fisher ..l82/39 Wheeland 182/39 Primary Examiner-Reinaldo P. Machado Att0rneyGlen B. Morse [5 7 ABSTRACT A guide follower assembly secured to the lower portion of an inclined ladder engages a downwardly open guide rail channel for stabilizing the position of the lower portion of a ladder with respect to the guide rails, the upper portion of the ladder being supported in conventional fashion by a follower engaging an upper guide rail. The ladder is inclined in a vertical plane parallel to the guide rails, and the lower follower is mounted on an arm extending preferably from the underside of the ladder, as inclined.

2 Claims, 7 Drawing Figures Patented A ril 24, 1973 2 Sheets-Sheet 2 r e k u m w T U e W n A ==zlh p w ATTORNEY SI-IIFTABLE LADDER INSTALLATION BACKGROUND OF THE INVENTION wardly open track rail was often recessed in the floor for stabilizing the position of the lower end of the ladder.

There are two principal difficulties with this standard arrangement. One of these is that the upwardly open guide rail in the floor tends to accumulate foreign material that interferes with the movement of the follower. The other problem results from the slanted position of the ladder, which necessarily leaves a triangular :portion at the end of the wall without access, if the lower guide rail must necessarily terminate at one extremity of the wall.

SUMMARY OF THE INVENTION The present invention provides a follower assembly engageable with a modified lower guide rail configuration. The lower guide rail is disposed a small distance above the floor, and has a downwardly open channel engaged by a follower element mounted preferably on an arm extending generally horizontally from the underside of the ladder. The rail configuration obviously eliminates any tendency to accumulate foreign material that will interfere with the movement of the ladder, and

the placement of the follower element on the arm makes it possible to move the lower portion of the ladder beyond the end ofthe guide rail. Situations are commonly encountered in which floor space is available beyond the end ofa panel or wall, and where the extension of the lower guide rail beyond the panel or wall is undesirable because of the obstruction involved resulting from its position above the floor. The present invention has been developed primarily in conjunction with service arrangements for communications panels, in which workmen are continually being required to work at various positions along a panel of substantial area containing various forms of junction equipment. The lower follower system is preferably equipped with a stabilizing bar which tends to maintain the lower extremity of the ladder in a predetermined position beside the lower guide rail.

DESCRIPTION OF THE DRAWINGS.

Thepreferred embodiments of the invention will be discussed in detail with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view illustrating 'a typical inclined ladder installation, as modified to include the present invention.

FIG. 2 is a sectional view on the plane 22 of FIG. 1,- on an enlarged scale.

FIG. 3 illustrates a typical arrangement for supporting the upper end of the ladder.- 1

FIG. 4 is a plan view, partially in section, showing the lower follower system and its supporting arm.

FIG. 5 is a side elevation of the assembly shown in FIG. 4.

FIG. 6 is a sectional view similar to FIG. 2, but showing a modified form of the invention.

FIG. 7 illustrates a further modification in the form of the lower guide rail.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the building structure in which the unit is installed includes a floor 10 and a ceiling 11. A service panel 12 defines a wall along which the inclined ladder 13 must move in order to provide access over the entire face of the panel for the convenience of workmen. The upper extremity of the ladder is equipped with at least one follower 14 engaging a guide rail 15 in the manner shown in FIG. 3. Frequently, this arrangement will be paired, with a follower on each side of the ladder, and engaging correspondingly spaced rails. In the FIG. 3 arrangement, the trough-shaped rail 16 is periodically supported by Z shaped brackets 17 secured to the ceiling with bolts or screws 18. A roller 19 is mounted on a stub shaft 20 secured to the end of a short strap 21 attached to the upper end of the ladder 13 by bolts as shown at 22 and 23. The stub shaft will normally have a portion of reduced diameter traversing the strap 21, and having a threaded section engaging a nut 24.

The lower extremity of the ladder is stabilized by the engagement of a follower assembly 25 with the lower guide rail 26. FIGS. 2, 4, and 5 illustrate this arrangement. The downwardly open channel 27 is secured to the rail 28 by bolts 29, and the rail 28 is supported by spaced brackets 30 through bolts 31. These brackets are mounted on the wall panel 12 with bolts as indicated at 32. The follower roller 33 is rotatably mounted on the upper end of the projection 34 secured to the angle bracket 35 with the nut 36. The bracket 35 is preferably welded to the bar 37, which forms one side of a fork embracing one leg of the ladder 13, as shown in FIG. 4. The bar 38 has one end welded to the bar 37 to form the other side of the fork, and the ladder 13 is clamped between the sides of the fork by the bolts 39-42. Where it is practical to do so, it is desirable to have at least some of these bolts traversing the material of the ladder to increase the security of the arrangement, and to assure the continued horizontal position of the bar 37. The lower extremity of the ladder will normally be equipped with the usual rollers 43, which can be mounted in any conventional manner.

The stability of the position of the bar 37 about a vertical axis of possible rotation is maintained by the presence of the stabilizing bar 44 secured to the projection 34 by the bolt 45 in position to bear against the side of the channel rail 27. This arrangement assures that the rollers 43 will continue to track fairly close to a predetermined path as the ladder is continually shifted from one position to another across the face of the wall panel 12. The guide rail 27 will usually be of steel, and

the use of brass for the bar 44 is recommended for the best wearing characteristics. It should be noted that the downwardly open position of the rail 47 lends itself well to the application of grease or other lubricant, without danger of fouling the surrounding area.

FIG. 6 shows a modified form of the invention, with regard to a possible structure for the lower guide rail.

The follower assembly 46 is identical to that shown in FIG. 2, with the roller engaging a downwardly open channel rail 47 which is equivalent in function to the rail 27. The use of the rail 48 in place of the rail 28 makes it possible to position the rail 47 at a greater distance above the floor, where the primary rail 49 (which is equivalent to the rail 30 of FIG. 2) happens to be placed at such a position where a higher vertical position of the rail 47 is desired. These rails are easily secured with bolt-nut assemblies in the conventional manner. FIG. 7 illustrates a further modification where it is desirable to obtain a somewhat smaller elevation of the channel than is provided by the FIG. 6 assembly. A channel configuration is provided by the rail 50, which has a special cross-section operating in conjunction with the downwardly extending flange 51 of the rail 52. The rail 52 is mounted in the position of the rails 49 and 50, and it is obvious that the FIG. 7 assembly has fewer components than those previously described. Where the number of installations justifies the use of the special cross-section of the rail 50, the FIG. 7 arrangement is very advantageous when the vertical position of the guide channel is somewhat higher than that of the principal base rail normally secured to the wall panel 12.

I claim:

1. A shiftable ladder installation including a building structure having a floor, an upper guide rail, a ladder having follower means engaging said upper guide rail, and a lower guide rail parallel to said upper guide rail and disposed above said floor, said ladder being inclined in a vertical plane parallel to said rails, wherein the improvement comprises:

means on said lower guide downwardly open channel;

follower means secured to said ladder and including an element extending upwardly and received within said channel, said element being secured exclusively to an arm extending substantially horizontally from the under side of said ladder, as inclined, said arm having a fork receiving a portion of said ladder and secured to said ladder by securing means. 2. A shiftable ladder installation including a building structure having a floor, an upper guide rail, a ladder having follower means engaging said upper guide rail, and a lower guide rail parallel to said upper guide rail and disposed above said floor, said ladder being inclined in a vertical plane parallel to said rails, wherein the improvement comprises:

means on said lower guide downwardly open channel;

follower means secured to said ladder and including an element extending upwardly and received within said channel; and

a stabilizing bar adjacent to said element and disposed within and extending along said channel for bearing engagement with the sides of said channel.

rail defining a rail defining a 

1. A shiftable ladder installation including a building structure having a floor, an upper guide rail, a ladder having follower means engaging said upper guide rail, and a lower guide rail parallel to said upper guide rail and disposed above said floor, said ladder being inclined in a vertical plane parallel to said rails, wherein the improvement comprises: means on said lower guide rail defining a downwardly open channel; follower means secured to said ladder and including an element extending upwardly and received within said channel, said element being secured exclusively to an arm extending substantially horizontally from the under side of said ladder, as inclined, said arm having a fork receiving a portion of said ladder and secured to said ladder by securing means.
 2. A shiftable ladder installation including a building structure having a floor, an upper guide rail, a ladder having follower means engaging said upper guide rail, and a lower guide rail parallel to said upper guide rail and disposed above said floor, said ladder being inclined in a vertical plane parallel to said rails, wherein the improvement comprises: means on said lower guide rail defining a downwardly open channel; follower means secured to said ladder and including an element extending upwardly and received within said channel; and a stabilizing bar adjacent to said element and disposed within and extending along said channel for bearing engagement with the sides of said channel. 